Study links MRI tests, masectomies

Though magnetic resonance imaging, or MRI, has certainly advanced the field of diagnostic medicine, researchers at the School of Medicine have recently noticed an unintended consequence of the technology when used to diagnose breast cancer — an increase in breast removal surgeries.

A research team led by associate professor of general medicine Cary Gross and assistant professor of surgery Brigid Killelea reviewed Medicare data from 2000 to 2009 and found that women with breast cancer who received a preoperative breast MRI were later more likely to have one or both of their breasts removed in a procedure called a mastectomy. The study was published online in the journal Breast Cancer Research and Treatment on Aug. 14.

Although the study did not establish causation between MRI use and breast removal surgery, Killelea said the team can reasonably speculate why having an MRI would push women to choose a more aggressive surgery.

“MRI can really increase patient anxiety of developing breast cancer, but a lot of times this anxiety tends to be higher than the actual risk,” Killelea said.

Many of the lesions detected by MRI tests are not malignant, said assistant professor of surgery Anees Chagpar, another member of the research team. She added that women who receive an MRI sometimes have both breasts removed even if cancerous cells were only found in one.

The essential question, according to Chagpar, becomes whether the patient is opting for mastectomy because of personal values or because of heightened anxiety following an MRI.

Considering the great economic cost of mastectomies — the procedure is more expensive than ultrasounds or mammograms — as well as the personal psychological costs that come with breast removal, it is important that clinicians make sure MRI is being used appropriately, she added.

Gross explained that mastectomy is an appropriate option when there is significant risk of cancer recurrence. This study’s data set was comprised of women older than 64, who had low life expectancies and therefore less time for cancer to reappear, he said.

The team also highlighted the significance of discovering the correlation between MRI tests and higher numbers of aggressive breast cancer surgeries.

When MRI was first introduced, it became a routine part of medical examinations for cancer patients — but now, diagnostic oncologists are realizing that MRI is not always necessary and can even be detrimental, Chagpar said.

“I think there’s certainly a role for MRI, but as a medical community we have to think about and continue to study MRI so we can use it more appropriately,” Killelea said. “I’m not sure that every woman with newly diagnosed breast cancer needs an MRI.”

Gross agreed that this research calls attention to diagnostic imaging tests, which develop so quickly that they are never carefully evaluated. This study demonstrates that in some situations, MRI can “do more harm than good,” he said.

He added that the medical field has to find a proper balance between the risks and benefits of giving breast cancer patients MRI tests.

The study was supported by the National Cancer Institute, the P30 Cancer Center Support Grant and the Yale Comprehensive Cancer Center.